Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Physics
Characterization Of Laser-Generated Aluminum Plasma Using Ion Time-Of-Flight And Optical Emission Spectroscopy, Md. Haider A. Shaim, Hani E. Elsayed-Ali
Characterization Of Laser-Generated Aluminum Plasma Using Ion Time-Of-Flight And Optical Emission Spectroscopy, Md. Haider A. Shaim, Hani E. Elsayed-Ali
Electrical & Computer Engineering Faculty Publications
Laser plasma generated by ablation of an Al target in vacuum is characterized by ion time-of-flight combined with optical emission spectroscopy. A Q-switched Nd:YAG laser (wavelength λ = 1064 nm, pulse width τ ∼ 7 ns, and fluence F ≤ 38 J/cm2) is used to ablate the Al target. Ion yield and energy distribution of each charge state are measured. Ions are accelerated according to their charge state by the double-layer potential developed at the plasma-vacuum interface. The ion energy distribution follows a shifted Coulomb-Boltzmann distribution. Optical emission spectroscopy of the Al plasma gives significantly lower plasma temperature …
Aluminum Multicharged Ion Generation From Femtosecond Laser Plasma, Md. Haider A. Shaim, Frederick Guy Wilson, Hani E. Elsayed-Ali
Aluminum Multicharged Ion Generation From Femtosecond Laser Plasma, Md. Haider A. Shaim, Frederick Guy Wilson, Hani E. Elsayed-Ali
Electrical & Computer Engineering Faculty Publications
Aluminum multicharged ion generation from femtosecond laser ablation is studied. A Ti:sapphire laser (wavelength 800 nm, pulse width ∼100 fs, and maximum laser fluence of 7.6 J/cm2) is used. Ion yield and energy distribution of each charge state are measured. A linear relationship between the ion charge state and the equivalent acceleration energy of the individual ion species is observed and is attributed to the presence of an electric field within the plasma-vacuum boundary that accelerates the ions. The ion energy distribution follows a shifted Coulomb-Boltzmann distribution. For Al1+ and Al2+, the ion energy distributions …
Multicharged Carbon Ion Generation From Laser Plasma, Oguzhan Balki, Hani E. Elsayed-Ali
Multicharged Carbon Ion Generation From Laser Plasma, Oguzhan Balki, Hani E. Elsayed-Ali
Electrical & Computer Engineering Faculty Publications
Carbon ions generated by ablation of a carbon target using an Nd:YAG laser pulse (wavelength λ = 1064 nm, pulse width τ = 7 ns, and laser fluence of 10-110 J cm-2) are characterized. Time-of-flight analyzer, a three-mesh retarding field analyzer, and an electrostatic ion energy analyzer are used to study the charge and energy of carbon ions generated by laser ablation. The dependencies of the ion signal on the laser fluence, laser focal point position relative to target surface, and the acceleration voltage are described. Up to C4+ ions are observed. When no acceleration voltage is applied between the …
Spark Discharge Coupled Laser Multicharged Ion Source, Md. Haider A. Shaim, Hani E. Elsayed-Ali
Spark Discharge Coupled Laser Multicharged Ion Source, Md. Haider A. Shaim, Hani E. Elsayed-Ali
Electrical & Computer Engineering Faculty Publications
A spark discharge is coupled to a laser multicharged ion source to enhance ion generation. The laser plasma triggers a spark discharge with electrodes located in front of the ablated target. For an aluminum target, the spark discharge results in significant enhancement in the generation of multicharged ions along with higher charge states than observed with the laser source alone. When a Nd:YAG laser pulse (wavelength 1064 nm, pulse width 7.4 ns, pulse energy 72 mJ, laser spot area on target 0.0024 cm2) is used, the total multicharged ions detected by a Faraday cup is 1.0 nC with …